A systematic revision of Calotes Cuvier, 1817 (Squamata: Agamidae) from the Western Ghats adds two genera and reveals two new species
Author
Pal, Saunak
Author
Vijayakumar, S. P.
Author
Shanker, Kartik
Author
Jayarajan, Aditi
Author
Deepak, V.
text
Zootaxa
2018
2018-09-19
4482
3
401
450
journal article
29419
10.11646/zootaxa.4482.3.1
5916d93e-11d4-49c5-8085-8bcd37d3739b
1175-5326
1440674
10258391-162F-4C7D-AA5E-1A03A4F3FE19
Monilesaurus ellioti
(
Günther, 1864
)
comb. nov.
Calotes
rouxii—
(not of
Dum. & Bibr., 1837
), Jerdon, 1853. J. Asiat. Soc. Beng. (2) xxii, 1853: 471
Calotes ellioti
—
Günther, 1864
. Rept. Brit. Ind. 1864: 142.
Bronchocela indica
—Theobald, 1876. Cat. Rept. Brit. Ind. 1876: 105.
Calotes elliotti
—
Smith, 1935
. Fauna of
British India
, ii, 1935: 207.
Original description.
Günther, A. 1864
. The
Reptiles
of
British India
. London (Taylor & Francis), xxvii, 452 pp.
Taxonomic comments.
Monilesaurus ellioti
was described, based on Jerdon’s observation of
C. rouxii
like animals from “Malabar” in his list of
Reptiles
of
Southern
India
, 1853 and a collection of drawings of this species in the possession of W. Elliot. Historically, southern
Karnataka
and northern
Kerala
have been referred to as Malabar.
Boulenger (1885)
gave a short description of this species based on the collections made by Col. R.H. Beddome from Anamalai hills, Sivagiri Ghat, Tirunelveli and Malabar. As there are no
type
specimens associated with this species, we hereby designate a
neotype
for this species. The selection of the
neotype
is roughly congruent with the original
type
locality of this species “Malabar” as mentioned by Jerdon (1853). Murthy (1978) described a subspecies
Calotes ellioti amarambalamensis
the
type
locality of which is Amarambalam, Nilambur. The
holotype
of this species is now at ZSI Madras (ZSI Madras 159) (Das
et al
. 1998). We were unable to trace the specimen in ZSI collections despite repeated attempts. For now, the specimen may be considered as lost. Hence, we compare another specimen collected from the same locality (BNHS 1033), a female individual whose characters match well with other
M. ellioti
and the description provided by Murthy. Also, the locality is within the distribution range of
M. ellioti
and contiguous with the
type
locality. Therefore, we consider
Calotes ellioti amarambalamensis
as a junior synonym of
M. ellioti
(
Günther, 1864
)
. ZSI Madras 159 is wrongly mentioned as a
type
specimen of
Calotes ellioti
(
Uetz & Hošek, 2016
)
.
Neotype
.
CESL 0 45, adult male collected from Chembra reserve forest,
Kerala
by SPP, MVP and SPV on
10th June 2010
.
Other material examined.
ZSI 4325 gravid female & ZSI 4328 male collected from
Southern
India
;
CESL
0
42 adult
male collected from Manikunjamalai, Wayanad reserve forest,
Kerala
;
CESL
0
45 adult
male collected from
Chembra
reserve forest,
Kerala
;
CESL
0
47 adult
female collected from Vaithiri, Wayanad reserve forest,
Kerala
; CESL 0 57,
CESL
0 59 and
CESL
0
61 adult
females and
CESL
0 58 and
CESL
0
60 adult
males collected from Vallerimala, Wayanad reserve forest,
Kerala
;
CESL
0 77, adult female collected from
Arlam Wildlife Sanctuary
,
Kerala
;
CESL
0
33 adult
male collected from
Bonacord
,
Peppara Wildlife Sanctuary
,
Kerala
;
CESL 162
, adult male collected from Sholyar, Vazhachal reserve forest,
Kerala
;
CESL 204
, adult female collected from Pamba, Periyar tiger reserve,
Kerala
and
CESL
369 adult
male collected from Peppara, Cardemom hills,
Kerala
and
BNHS 1033
, adult female collected from
Nilambur
reserve forest,
Kerala
. Details of collection locality, specimen voucher and
GenBank
accession number in
Appendix
1.
Diagnosis and comparison.
A small sized
Monilesaurus
(SVL up to
73.8 mm
) characterized by the posteroventral orientation of lateral scales; antehumeral fold well developed, extending across the throat; 52–58 midbody scale rows; nuchal crest composed of 3–4 long, well developed spines; two separated supratympanic spines; a long, distinct isolated postorbital spine; dorsal and lateral scales keeled, ventral scales strongly keeled; paired postmentals, first pair separated by a single scale; 24–28 subdigital lamellae under fourth finger, 26–34 subdigital lamellae under fourth toe; 9–10 supralabials and 8–9 infralabials; olive brown above with angular darker cross bars on dorsum, a white spot below the eye.
Morphologically
M. ellioti
is superficially similar to
M. montanus
gen. et sp. nov
.
,
M. rouxii
comb. nov
.
; and
M. acanthocephalus
gen. et sp. nov
.
, but can be distinguished by a combination of the following characters: 52–58 midbody scale rows (vs.
46–52 in
M. montanus
gen. et sp. nov
.
,
62–64 in
M. acanthocephalus
gen. et sp. nov
.
, and
52–56 in
M. rouxii
) presence of a long, distinct isolated spine in the posterior corner of orbit (vs. absent in
M. rouxii
; very small, indistinct tubercle like in
M. montanus
gen. et sp. nov
.
, and much longer in
M. acanthocephalus
gen. et sp. nov
.
); 3–4 long nuchal spines (vs. 3–6 small nuchal spines in
M. montanus
gen. et sp. nov
.
, 6 much longer nuchal spines in
M. acanthocephalus
gen. et sp. nov
.
, 7–8 smaller nuchal spines in
C. rouxii
); longer, prominent isolated spine on the back of head and above tympanum (vs. much smaller in
M. montanus
gen. et sp. nov
.
, and
M. rouxii
) and presence of a white spot below the eye (vs. absent in
M. rouxii
; in the form of a band in
M. montanus
gen. et sp. nov
.
) and smaller body size: adult SVL
59.4–73.8 mm
, n=9 (vs.
C. montanus
gen. et sp. nov
.
, adult SVL
61–83.4 mm
, n=8; and
M. acanthocephalus
gen. et sp. nov
.
adult SVL
68.9–72.6 mm
, n=3).
Description.
Based on CESL 0 45. A medium sized adult male (SVL-
63.7 mm
), Morphometric and meristic data are summarised in Appendix 2 & 3. General habitus moderately compressed. Head moderately large (HL/SVL ratio 0.29), elongate (HW/HL ratio 0.63), maximum height less than maximum width; snout pointed; rostral broader than high; nostrils in single nasal shield, which is separated from rostral by a single scale; mental shield narrower than rostral; two postmentals, first pair in contact with each other; genials keeled; gular scales strongly keeled, slightly smaller than genials; scales on top of snout smooth except median row, which is keeled; scales on top of head heterogenous in size and shape, keeled; supraorbital scales keeled; canthus-rostralis and supraciliary edge sharp; a spine at the posterior corner of the orbit; two separated long spines on posterior end of head, the anterior slightly longer, midway between nuchal crest and tympanum, posterior above tympanum; orbit diameter 70% of distance between anterior border of orbit and snout tip; tympanum exposed, its greatest diameter 54% horizontal diameter of orbit; enlarged keeled scale between tympanum and orbit; posterior region of jaws swollen; supralabials 10/10; infralabials 9/9.
Nuchal crest well developed, composed of four primary, long conical spines, the first being the smallest and the third longest; the remaining vertebral scales slightly enlarged relative to adjacent rows and possess a more pronounced median keel forming a serrated ridge like the dorsal crest which continues till the tail base; 54 longitudinal scale rows around midbody; scales on dorsum keeled, oriented postero-dorsally, while lateral ones oriented postero-ventrally; lateral scales smaller than dorsal, keeled; ventrals strongly keeled, irregular, slightly smaller than dorsals but of similar size as laterals, genials and gular scales; a strong, oblique antehumeral fold, nearly extending across the throat.
Limbs slender and covered with strongly keeled scales, larger than laterals, forming parallel longitudinal rows; scales under thighs weakly keeled; length of hindlimb ca. 87% SVL; relative length of fingers 4>3>2>5>1; relative lengths of toes 4>3>5>2>1; fourth toe longer than fifth finger; 23 subdigital lamellae under fourth finger; 27 subdigital lamellae under fourth toe; subdigital lamellae with sharp keels, bicarinate; tail slender, swollen at the base; scales on dorsal and ventral surface of tail with sharp keels, larger than laterals; tail length
172 mm
.
Colouration.
In life: dorsum and head blackish-brown with irregular lighter patches on the back; a light brown band from above the shoulder till the dorsal crest forming a ‘v’ shape; head laterally dark blackish with a white spot below the posterior end of eye; stripe from above nostril to anterior margin of orbit extending till the tympanum from the posterior margin of orbit in the form of a black band; tympanum pale grey, lip scales white; a blackish triangular patch behind the tympanum continuing to the antehumeral fold; ventral uniformly lighter, pale grey; gular pouch with a reddish stripe extending beyond the throat; tail with alternating dark and light blotches forming irregular bands towards the end. Representative image showing live colouration (
Fig. 6b
). In preservative: colouration pattern mostly similar to that in life, except overall paler; bands on the head dull greyish brown.
Variation and secondary sexual characteristics.
The other specimens examined agree with the CESL 0
45 in
general morphology and scalation except for some differences that are summarised in Appendix 2 & 3. All the examined female specimens (CESL 0 47, CESL 0 58 and CESL 061) have much smaller nuchal spines compared to the males, reduced postero-orbital spine; lack a dorsal crest and gular sac; overall colouration olive-brown, lighter head and vertebral region, a dark band along the side of the head to the neck and presence of a black antehumeral fold.
Genetic distance.
M. ellioti
comb. nov
.
shows 1–2% intraspecific genetic divergence in the 16S gene; 4–7% interspecific genetic divergence from
M. rouxii
comb. nov
.
; 5–7% interspecific genetic divergence from
M. acanthocephalus
gen. et sp. nov
and 4–8% interspecific genetic divergence from
M. montanus
gen. et sp. nov
.
(Appendix 5).
Distribution.
Monilesaurus ellioti
comb. nov
.
is endemic to the
Western
Ghats and is distributed across the low and medium elevation forests (up to
1000 m
asl) of southern parts of central
Western
Ghats (Coorg plateau and south) and the southern
Western
Ghats. This is one of the most common evergreen forest dwelling agamid lizards in this region. During this study,
M. ellioti
comb.nov.
was recorded in various sites in the central and southern
Western
Ghats (See
Fig. 3
& Appendix 1 for details).
Ecology and natural history.
Monilesaurus ellioti
is a diurnal lizard, semi-arboreal to arboreal in habit, and so far, has been recorded mostly in semi-evergreen and evergreen forests. Individuals were mostly seen perching on shrubs, branches and actively moving on tree trunks. In some instances, it has also been observed in coffee plantations surrounded by evergreen forests. In some sites like Parambikulam, Vazhachal reserve forest and Brahmagiri hills, it was observed to occur syntopically in the same habitat as
M. rouxii
comb. nov
.
, but more abundant within dense forests, while
M. rouxii
comb. nov
.
is generally restricted to forest edges. In some instances, gravid females were recorded during pre-and mid monsoon (June–August), which hints that monsoon might be a breeding season for this species.